Answer:
a. 58.5 g/mol
b. 0.1 mol
Explanation:
a.
The molar mass of Na is 23.0 g/mol. The molar mass of Cl is 35.5 g/mol. The molar mass of NaCl is:
M(Na) + M(Cl) = 23.0 g/mol + 35.5 g/mol = 58.5 g/mol
b. A healthy adult should eat no more than 6 g of salt in one day. The moles corresponding to 6 g of NaCl are:
6 g × (1 mol/58.5 g) = 0.1 mol
Half life is the time taken by a radioactive isotope to decay by half its original mass. In this case, the halflife of the radioactive isotope is 5000 years.
Initially the mass is 100 %; thus the mass that will be left will be given by;
New mass = Original mass × (1/2)^n where n is the number of half lives;
n = 10000/5000 = 2
New mass = 100% ×(1/2)^2
= 100 % × 1/4
= 25%
Therefore; the mass left after 10000 years is 25% or 1/4 of the original mass.
Answer:
all good. tell me about your day
Answer:
[KOH] = 0.10M in KOH
Explanation:
Molar Concentration [M] = moles solute/volume solution in liters
moles KOH = 0.56g/56g/mole = 0.01mole
Volume of solution = 100cm³ = 100ml = 0.10 liter
[KOH] = 0.01 mole KOH / 0.10 liter solution = 0.10M in KOH
